Target for storage tubes of the cathode beam type



Nov. 18, 1952 R. SNYDER, JR

I TARGET FOR STORAGE TUBES OF THE CATHODE BEAM TYPE Filed April 12, 1945 2 SHEETS-SHEET 1 1N VEN TOR. Zahara L. J12

flu 81,112

ATTORNEY Nov. 18, 1952 R. 1... SNYDER, JR

TARGET FOR STORAGE TUBES OF THE CATHODE BEAM TYPE 2 SHEETS-SHEET 2 Filed April 12, 1945 X QQQ INVENTOR. Jz'zydel; (fir W 8 m x 89 Rickard L.

ATTORNEY:

Patented ov. 18,, 1952 TARGET FOR STORAGE Tunas oE'rnE CATHODE BEAM ma Richard L. Snyder, In, Princeton, N. 3., assignor to Radio Corporation of America, a corporation of Delaware Application April 12, 1945, Serial No. 588,047

9 Claims. .1 This invention relates to cathode beam storage tubes.

In my application, filed April 25, 1945, Serial No. 588,046, a multiplicity of spaced conducting strips are plated on a mica sheet and the tops of these strips are transversely scanned at a ful target, it entails considerable trouble and care to insure that the strips are isolated from each other and are of the required minute width.

It is an object of this invention to devise an improved target in which the conducting strips can be efliciently constructed with minimum care.

Another object of the invention is to provide a storage target having conducting strips for transverse scanning, having such construction that the conductivity from one end to the other can .be assured with minimum supervision of construction methods.

Another object of the invention is to provide a target for transverse scanning by two beams of difi'erent character, in which the conducting strips are made of wires.

Other objects of the invention will appear in the following description, reference being had to the drawings, in which:

Figure 1 is a sectional view of an improved form of target, the section being taken on the line Il of Figure 2, viewed in the direction of the arrows.

Figure 2 is a front elevation of a portion of the target shown in Figure 1, the left-hand side 4 of the target being broken away for convenience of illustration.

Figure 3 is a sectional elevation of a modified form of target, taken on the line 3-3 of Figure 4.

Figure 4 is an elevation of the target of Figure 3, the middle portion of the target being broken away to reduce the size of the figure.

Figure 5 is a diagrammatic illustration of a known form of cathode beam tube and circuits, for explaining the operation of my invention.

Referring to Fig. 1 of the drawing, a series of conducting wires I are stretched taut and accurately spaced apart between two insulation sheets 2R3 of some material such as mica. Two metal plates 4 and 5 are placed on opposite sides of the mica sheets, as shown, and pressed firmly together in suitable dies so as to be deformed with transverse channels 6 and 1, so as to hold the wires and sheets firmly in position, as well as to give'the assembled unit the desired rigidity. .The metal plates #3 and 5 are indicated as being of'rectangular shape and extend sufficiently beyond the side of the mica sheets (shown in dotted lines at 8) so that the two plates can be welded together, for example by spot or line welding, as at 9, to hold the parts rigidly together.

Figure 2 is broken away to reduce the size of the figure, but it will be understood that the left-hand part of the figure, not shown, will be similar to that illustrated in the figure and that the target will be of suflicient width to accommodate the desired number of conducting wires I, which, for example, may be fifty per inch.

In the modification of Figs. 3 and 4, means are provided for clamping the wires together in spaced relation at both ends of the scanned portions. In this modification the wires Ill, analogous to the wires I of Fig. 1, are placed between two mica sheets ll, 12 in proper spaced relation. The mica sheets have aligned cut-out portions or windows I3, It adjacent one end and similar cut-out windows l5, I6 adjacent the other end. Metal plates ll, 8 are placed on opposite sides of the assembled mica sheets and parallel wires with two transverse metal rods 19 and 28 placed between one plate, say H, and the mica sheet It. The plates ll, l8 are preferably previously formed with out-turned ends 2!, 22 and 23, 26, respectively, and with a plurality' of reinforcing ribs 25 before being placed in the assembled position referred to. The ribs are, of course, to give the plates rigidity and strength. The plates H and It also have windows 26, 21 and 28, 29 cut out so as to suitably align with the windows in the mica sheets when assembled as described. The assembled parts are then placed in a press with appropriate dies and pressed around the rods I9 and 241 until they are in firm contact, as shown in the drawing. The wires are thus held in firm position at the tops and bottoms of the windows and care need not be taken to prevent displacement of the outside ends, as in the embodiment of Fig. 1.

While the parts are clamped together in the dies, caps 3t, 35 are fitted against the out-turned ends 22, 2d and El, 23, respectively, and welded thereto, though the plates may be fastened together in other ways, as by welding around the edges by extending the plates a sumcient distance beyond the mica sheets. When the elements are thus' assembled and joined together, they make a rigid unit in which the transverse wires l0 are held in accurate spaced relation across the windows.

My improved targets may be used in any desired form 01 cathode beam tube, except that 4!, 400. are made the top,

the bottom of apropos their associated elements are employed therein. I have illustrated a suitable known form in Fig. 5, with the form of target illustrated in Figs. 1 and 2 and, of course, it will be understood how the embodiment of Figs. 3 and 4 may likewise be used therein.

In Fig. 5 the cathode beam tube has, inside the evacuated envelope II, a gun with the usual cathode 33. grid I4, first anode l5, and second anode it and the associated horizontal deflector plates I1, 38 and vertical deflector plates 39, 40. The other gun has similar parts and elements, designated by similar reference characters except the subscript a has been added to distinguish the parts and associated elements of one gun from the other and these need not be specifically referred to. The two deflector plates in the form of a T, Joined together, and having the shank of the T extending eoaxially with the tube to shield one gun and its associated elements from the other. Metal plates two guns and 4|, 4la. with suitable apertures serve as additional shields. The target of Fig. 1 employed in the tube has shield-plates 42, 43, 44 spaced above and below the free ends of the wires 1 at as shown in the figure, and similar shield plates above and below the ends of the wires at the target, as shownin the figure. Since it is assumed, by way of example, that my improved form of targets will be used in a radar system,-I have illustrated the usual in such a system in block diagram.

Various potentials may be applied to the elements of the tube, but by way of example I have indicated that the two cathodes 33 and 33a may be connected to the 1,000 volt negative terminal or a source of supply and that the grids 34, 34a

parts .may be connected to their respective cathodes through a suitable resistance and negative bias source, a suitable value being in the neighborhood of 20 volts. The cathodes may be heated with the usual heater. The first anodes of the two guns may be connected to the 800 volt negative terminal and the second anodes may be grounded to a terminal 1000 volts positive, relative to the cathode. If one supply unit is to be employed for all of the voltages, this ground may be the plusminus terminal, so that certain elements may be made positive thereto. The deflector plates 31, 38 for the upper beam are connected to a suitable saw-tooth generator 45, which may have, say, a frequency of 400 cycles per second. Sawtooth generators for use in television circuits are well known and this need not be specifically described. The vertical deflector plates 39, 40 of the upper tube are used merely to Position-the beam in the desired horizontal scanning line and therefore they are connected to a direct current source, the plate 40 being connected to ound and the plate 39 being connected to a suitable positive terminal in the supply unit to position the beam 49 of the gun in a horizontal line at an intermediate portion of the wires protruding from the target or extending across the windows, if the embodiment of Fig. 3 be used. The shield plates 42, 43, 44 of the upper gun may be connected to the 100 volt negative terminal.

The parts associated with the lower gun may be connected to the same voltage terminals as used for the upper gun, except the horizontal deflector'plates 38a and 310 are connected to a saw-tooth generator of a lower frequency, say 2 cycles per second, and the shield plates 42a. 43a and 440 are connected to the 200 volt positive a terminal of the suppiy.

associated 4 The saw-tooth generator 45 ismaintained at constant frequency by a suitable synchronizing device 46 and this also pulses the transmitter 41. This synchronizer-pulser and transmitter may be or known form, to radiate a pulse in the desired direction at the beginning of each cycle of the saw-tooth. generator 45. The receiver 48 may have the usual. elements with a directional dipole antenna for receiving the signal pulses reflected back by. distance objects. The signal receiver is connected through a suitable condenser to the grid 34 of the upper sun. so that the received signal intensity-modulates the cathode beam 49. The beam 50 of the lower gun is not modulated, but adjustments are such that it is always of greater current strength than the peak values of the modulated beam 49, for reasons that will be later apparent. The plate of the target remote from the gun, such as 5, may act as a signal plate and it may be connected through a suitable condenser 5| to the input circuit of any desired form of indicator 52, which may be a facsimile recorder, for example like the one disclosed in the patent of Charles J. Young, 1,848,862, March 8, 1932, or any other suitable indicator such as an oscilloscope.

the wires may be positioned and electrically connected as indicated in Fig. 3.

The manner in which my improved target may be used in a signal system for locating battleships, airplanes and other distant objects will now be explained, with reference to Fig. 5.

Assume that no signal, for the moment, is being received. As the lower unmodulated beam 50 sweeps transversely across the wires I at the bottom of the target, they will be brought to the plus 200 volt potential of shields 42a, 43a, 44a by secondary emission, the secondaries being collected by the shields. The wires may be coated with some active material, say beryllium, to insure a copious secondary emission ratio considerably greater than unity. Having explained how the reference potential of the wires is obtained, it may now be assumed that the signal pulses are transmitted by 41 at the beginning of each saw-tooth cycle of generator 45. These will be reflected by stationary and moving objects, if these be in the line of transmission. The transmitted pulses are reflected back and received at 45 at times varying with the distance of the object from the transmitter. The received, detected and amplified signal pulses modulate beam 49 and as this beam makes each sweep transversely across the top portions of wires I, the potential of the wires will be reduced below the reference potential an amount proportional to the signals modulating the beam at the instant the beam strikes the wires. This reduction is due to the fact that the shield plates 42, 43, 44 are negative relative to the wires and secondary emission is suppressed. As the beam 49 repeatedly sweeps across the wires, the reduction in potential will be incremented by electrons received from the beam until on the 400th cycle a maximum value of a series of signals will be impressed on the multiplicity of wires l, reppotential of the wires causes displacement current to flow through condenser 5i and resistance to ground, which is recorded by the indicator 52.

After each strip is brought to reference potential by beam 50, beam 49 starts storing increments of signals thereon and these in turn will be again discharged by beam 50. Stationary objects will reflect signals in constant phase or time position and will not appear to move across the paper of the recorder or other indicator 52,, but will assume constant position thereon. A moving object, say an airplane, will constantly vary its distance from the transmitter 41 and thus vary its phase or time position on the target or other record of the indicator. Thus, its position and direction of motion is determined and recorded as a diagonal line across the facsimile recording sheet.

By storing the signals in the way indicated, maximum effects are produced and position locatitan is rendered correspondingly more accura e.

Having described my invention, what I claim ated enclosure containing a target comprising a multiplicity of spaced parallel conductors, means for clamping said conductors in rigid position intermediate their ends, means for producing a modulated and an unmodulated beam, means for scanning the modulated beam transversely across the conductors adjacent one of their ends at a predetermined rate to store signal charges thereon, means for scanning the unmodulated beam transversely across the other of their ends at a lesser rate and means for discharging the signals stored in said conductors upon the scansion of the conductors by the unmodulated beam.

3. In cathode beam storage tubes, a target comprising a sheet of insulation, a multiplicity of parallel and spaced conductors having ends extending beyond the edges of said sheet and insulating means for compressing said conductors against said sheet.

4. In cathode beam storage tubes, a target comprising two sheets of insulation, a. multiplicity of parallel and spaced conductors between said sheets having ends extending outside thereof and a pair of metal plates enclosing said insulation sheets and compressing them against the conductors, said plates being fastened together to hold said conductors in rigid position between the insulation sheets.

5. In cathode beam storage tubes, an evacuated enclosure containing a target comprising two sheets of insulation having windows adjacent the ends,'a multiplicity of parallel and spaced conductors between said sheets extending across said windows and a pair of metal plates having windows adjacent the ends enclosing said insulation sheets and compressing them against the conductors, all said windows adapted to align 6 with each other, whereby the conductors are exposed therethrough, and means for fastening said plates together at their ends.

6. In cathode beam storage tubes, a target comprising two sheets of insulation, a multiplicity of parallel and spaced conductors between said sheets, and a pair of metal plates enclosing said insulation sheets and compressing them against the conductors, all said sheets and plates having aligned windows whereby said conductors are exposed therethrough, said plates being fastened together adjacent the ends of said conductors.

7. In cathode beam storage tubes, a target comprising two sheets of insulation, a multiplicity of parallel spaced conductors between said sheets, two metal plates, said sheets and plates having windows adapted to ali n with each other with the conductors extending thereacross, a rod adjacent each window extending transversely of said conductors, said sheets, conductors and one metal plate being on one side of said rods and bent partly therearound to hold said rods in rigid position. and the other plate being on the other side of said rods and bent in the reverse direction therea'round, and means to fasten the ends of said plates together.

8. A transmitting storage tube comprising an envelope, an insulation sheet in said envelope having a plurality of conductors extending across one of its surfaces, a put-on cathode beam gun adapted to have a signal modulated beam, means for scanning the beam of said gun transversely across one section of said conductors, a take-off cathode beam gun having a beam of greater intensity than that of the first gun, means for scanning the beam of the take-off cathode beam gun across another section of said conductors at a lesser rate than that of the first mentioned beam, an electrode adjacent last of said sections for collecting secondary electrons emitted thereby, one of said electrodes having a positive potential relative to that of the other and a signal plate on the other surface of said insulation sheet.

9. A transmitting storage tube comprising an envelope, an insulation sheet in said envelope having a plurality of conductors extending across one of its surfaces, at put-on cathode beam gun adapted to have a signal modulated beam, means for scanning the beam of said gun transversely across one section of said conductors, a take-off cathode beam gun having a beam of greater intensity than that of the first gun, means for scanning the beam of the take-oil cathode beam gun across another section of said conductors at a lesser rate than that of the first mentioned beam, an electrode adjacent last of said sections for collecting secondary electrons emitted thereby, the electrode adjacent the take-oif section of said conductors having a positive potential relative to that of the other electrode.

RICHARD L. SNYDER, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,133,123 Tihanyi Oct. 11, 1938 2,179,205 Toulon Nov. '1, 1939 2,186,393 Ring et a1 Jan. 9, 1940 2,273,793 Ekstrand Feb. 17, 1942 2,283,148 Bruce May 12, 1942 

